Ground-clamp.



UNITED STATES PATENT OFFICE.

HERBERT B.

ANDREWS,'WILLIAM H. HART, AND HOWARD B. SHERMAN,

or BATTLE CREEK, MICHIGAN, ASSIGNORS TO H. B. SHERMAN MANUFACTURINGCOMPANY, OF

BATTLE GREEK, MICHIGAN,

A CORPORATION OF MICHIGAN.

GROUND-CLAMP.

specification of Letters Yatent.

Application filed May 31, 1916. Serial No. 100,897.

being bad to which form as copper and will be strengthened at the wherethe bolt head is applied so thatpoint such head will not tear the clamp;and which will have a holder or socket for engagement with the end of awire; and'whereby tipping of theends of the clamp together, before it isproperlytightened around the object to which it is applied, will bePIG-r vented; and which clamp can be readily applied to an object suchas a rod or pipe.

The invention consists in the novel construction of the clamp ashereinafter de-; scribedand illustrated in the accompanying drawings,and the essential features of construction for which protection isdesired are summarized in the claims.

In said drawings:

Figure 1 is a perspective view of our ground clamp as applied to a pipe,and showing a wire connected therewith.

Fig. 2 is an enlarged vertical sectional view through the ears of theclamp in the plane of the bolt. s Fig. 3 is a similar sectional Viewthrough the socket portion of the clamp.

Fig. 4. is a transverse or horizontal section through the clamp in theplane of the bolt. 7 Fig. 5 is an inside view of the countersunk ear ofthe clamp.

Fig. 6 is a reverse view of Fig. 5.

Our ground clamp, as shown, comprises a body preferably made of a stripof soft which is a good conmetal, such as copper,

This body can be bent ductor of electricity.

as shown to facilitate its application .to a

pipe, rodor object to which the clamp is to be applied; and one end ofthis body forms an ear 1 in which is an opening 1 for the passage of asecuring bolt 2. Partially surthe ear is a recess or counter-sink 1clear, and exact on the exterior of preferably produced by stamping themetal,

rounding this opening 1* and when so produced forming a projection l onthe inside of the ear (Fig. 5). The said countersunk 'portion isinclined to the body of the'ear so as to give the head of the bolt afull bearing against such ear, as indicated in Fig. 4. The edge of theopening 1 within this recess is preferably flanged as at 1. I v

Said recess or counter-sink 1 helps to stiffen the metal around the bolthead, where the strain ordinarily first comes, and where tearing wouldordinarily begin; and said counter-sink also provides a place where aPatented Oct. 2, 1917.

small wire might be secured beneath the head 2 of the screw 2, in caseit was desired to attach a wire to the clamp at this point.

The head of the. bolt 2 would be apt to cut or burst through.thelopening in the ear,

when the clamp was applied to an object and the bolt 2 tightened; butthe countersink 1. prevents'such tearing through, and it provides alarge fiat bearing for the inner edge of the bolt head. The flange 1'around the edgeof the opening 1"" also greatly reinforces andstrengthens same and prevents the bolt tearing out or enlarging theopening.

At the outer end of this ear l-the extrem-"- secured a cartridge orthi'nble 3 (Figs. 8

and 4;) closed ,at one end andopen at the other end. Said thimblemay beformed by drawing a suitable metal shell to fit into the loop, and suchshell canybe readily secured in the loop by dipping same in molten tinor solder. Said shell is adapted to hold solder, and when the clamp isapplied to a rod orpipe so a vertical position. closed end of thesocket. should be at the bottom so that'hot solder can be placed in thesocket, or the socket heated to melt. the solder, and the end of a'wi-reW can be inof the body is bent upon itself to form a that the shell'orsocket is in (as in Figs. land 3) the" sorted in the socket as indicatedin (Figs. 1,

3 and 4) and be' securely fastenedthereto,

or the end of a wire can be coatedjwithj tin the shell' prevents thehot' -so1 der dropping out of the socket when. the same is hot, and

when the end'of the wire is inserted therein. If the shell were not usedand it was attempted to heat solder in the looped end, or to place hotsolder therein, the solder would.

' run out of the end of the loop, and it would be difficult to close upone end of the loop suficiently to hold the solder, as hot solder willrun out of joints which would hold water.

Preferably a flat brass washer a is placed on the bolt between the head2 and the ear. Such washer fits in the counter-sink 1 as shown anddecreases the friction of the bolt head on the metal, and givesadditional security against possibility of the bolt head digging into orcutting the metal. Such washer also assists in preventing impropertipping or bending the ears out of shape when the clamp'is fastened to arod or pipe.

The clamp body may be provided with a series of perforations 1 adjacentits other end, with one of which perforations the bolt 2 is engaged whenthe clamp is applied to a rod or pipe. The nut 2 on the bolt engages theend of the clamp opposite the ear 1 as shown; and enables the clamp tobe very easily and firmly secured to an object.

The looped end 1 of the ear 1 also performs the function of preventingthe ears or ends of the clamp tipping together too quickly, and spacesthe outer ends of the ears apart, and thus enables the bolt 2 to tightlysecure the clamp to the object. The looped end of the clamp insures thatthe clamping strain on the bolt and nut will be equally distributed atthe bottom or inner ends of the ears as well as the top or outer endsthereof, and thus insures that the'body of the clamp gets a larger andbetter surface contact with the rod or pipe to which it is applied.

The washer l not only prevents the head of the bolt digging into themetal, but it also serves as a convenient means to enable a wire to befastened around the bolt beneath the head and between the washer and thebottom of the counter-sink or body of the ear.

With such ground clamps electric connec tions can be made either bysoldering the end of the wire in the socket or looped end of the body;or by bending the end of a wire around the bolt between the brass washerand the ear. In the latter case the depression or counter-sink in theear forms an excellent retainer for the end of the wire.

In constructing the clamps, instead of punching the bolt opening in thecountersink full size, We prefer to make it small and then eniarge it byturning down its edge to form. {Clf'r flange 1 and by thus Hangingmenses the metal around the bolt opening the copper is reinforcedat theweakest point, and the clamp bolt can be applied very tightly withouttearing the opening, or the head of the bolt bursting through theopening.

The principal essential and novel features of our ground clamp are, thelooped or socketed end, the depression or counter-sink for the head ofthe bolt, the flange around the opening beneath the bolt head, the shellin the looped end, and the washer engaging the bolt and fitted withinthe counter-sin or depression.

l Vhat we desire to protect is set forth in the following claims.

1. A ground clamp formed of a strip of suitable metal, and provided atone end with a loop, and a shell in said loop closed at one end.

2. A ground clamp formed of strip of suitable metal, having a stampedcountersunk portion with an opening for the engagement of the head of abolt, the said countersunk portion being inclined to give the head ofthe bolt a fullbearing against the ear; and the edge of said openingbeing flanged to reinforce same.

3. A ground clamp formed of a strip of suitable metal, having a stampedcountersunk portion with an opening in said portion for the engagementof the head of a bolt, the said countersunk portion being inclined togive the head of the bolt a full bearing against the ear.

4. A ground clamp formed of a strip of suitable metal, provided at oneend with a loop for the engagement of a wire, a counter-sink adjacentsaid loop, and a bolt opening in the counter-sink, the edge of saidopening being flanged.

5. A ground clamp formed of a strip of suitable metal, provided at oneend with a socket for the engagement of a wire closed at one end, and acounter-sink adjacent said soiket having an opening for the passage of aolt.

6. A ground clamp formed of a strip of suitable metal, provided at oneend with a loop for the engagement of a wire, and an inclinedcounter-sink adjacent said loop having an opening for the passage of abolt; with a bolt and a washer thereon adapted to engage thecounter-sink.

In testimony that we claim the foregoing as our own, we afiiX oursignatures.

HERBERT B. ANDREWS. WILLIAM H. HART. HOWARD B. SHERMAN.

